HURLEY — The problems began when Ruth Gallo brought her dog up to her home in the hamlet of West Hurley for a couple of days.

Maggie, a 4-year-old terrier mix, had developed a horrific cough, said Gallo's husband, Kevin Meehan.

A March 4 trip to the Kingston Animal Hospital found Maggie had a high temperature. The hospital kept Maggie for the night and put her on antibiotics. Within four days, veterinarian Dr. Arnold Rugg at the animal hospital said Maggie's lungs had cleared out and her coughing had stopped.

Maggie lives with Gallo in Greenwich Village and spends much of her time in day care. New York City is America's top hotbed for dog flu, said Dr. Edward Dubovi of Cornell University's College of Veterinary Medicine, and dogs experiencing close contact with other dogs in shelters, kennels or day care are most vulnerable.

The spread of the flu from Maggie to Harvey, an 11-year-old German shorthaired pointer who lives in West Hurley with Meehan, was more serious. Harvey exhibited a slight cough March 8, then pooped in the back of the car en route to the Kingston Animal Hospital.

"That was the sign of something serious," Meehan said. "That was something we would never normally do." The doctors said Harvey had a temperature of 106.4 degrees, 5 degrees above normal. He had a severe cough and had stopped eating, meaning Meehan had to force his mouth open to give him amoxicillin tablets wrapped in some meat.

"It was just the most painful thing," Meehan said. "The thought of losing him was more that I could bear."

It took intravenous therapy and a week of antibiotics to nurse Harvey back to health.

"Those two dogs would have died without treatment," Rugg said, noting both Maggie and Harvey caught bacterial diseases while weak from the flu.

Dog flu was first identified in 2004 and has now been documented by researchers in 39 states. It's typically brought to other parts of New York state by dogs that spend time in New York City, said Dubovi, director of virology at Cornell's Animal Diagnostic Center. Dog flu is typically a mild respiratory infection marked by coughing, sneezing or difficulty breathing, Rugg said. Nearly 10 percent of infected dogs will die from bacterial diseases caught while under the flu.

Vaccination will keep dogs immune from catching the flu. The vaccine and booster cost about $65 the first year and $30 in subsequent years.